1. The Field of the Invention
The present invention relates to compositions for coloring keratin fibers, particularly human hair, based on a developer-coupler combination and direct dyes which compositions make it possible to impart to the fibers a lasting coloration without the addition of an oxidant (comparable to the sta-bility of semipermanent colors) while at the same time causing only minor damage to the fibers (comparable to temporary hair dyes).
2. The Related Art
In the field of keratin fiber coloring, particularly hair coloring, oxidation dyes have attained substantial importance. The coloration is formed by reaction of certain developers with certain couplers in the presence of a suitable oxidant. For very gentle uses, however, the need exists for colorants which in the presence of atmospheric oxygen give lasting colorations even without the addition of an oxidant.
It is known from EP 1 166 748 A2 that the combination of oxidation dyes and optionally direct dyes can be used for hair dyeing without the addition of a chemical oxidant. Constant coloring results (namely a coloration that is the same immediately after the use as well as days or weeks thereafter) are not possible with the agents described in that document.